The embodiments of the invention relate to an inkjet recording apparatus, and particularly relate to an inkjet recording apparatus in which an ink in an ink container is stirred and ink particles are continuously ejected.
An inkjet recording apparatus of a continuous system performs recording by sucking an ink from an ink container with a pump, supplying the ink to a nozzle through an ink filter and a pressure regulating valve which regulates the pressure of the ink, applying oscillation to the ink ejected from the nozzle to generate ink particles, and charging and deflecting the ink particles so as to allow the ink particles to reach a recording medium. Further, the apparatus adopts a circulation mechanism in which the ink is continuously ejected from the nozzle, and the ink particles which are not used for recording are collected by a gutter unit and returned to the container storing the ink by the force of the pump, and then, supplied to the nozzle again.
In the case where printing is performed on the surface of a recording medium of a dark color such as black, when a widely used dye-based ink is used, letters printed with a similar color to the color of the surface of the recording medium are hard to read, and therefore, printing is performed using a pigment-based ink of a bright color such as white or yellow, or printing is performed using a complementary color.
The pigment-based ink has a problem that when it is left as it is in a container which stores the ink for a long period of time, a pigment which is one of the components of the ink precipitates. When the ink is circulated by supplying the ink to a nozzle and collected while keeping the pigment precipitating, clogging occurs in the circulation path. Further, unevenness occurs in the color tone for printing on a recording medium, and therefore, a trouble that it is difficult to recognize the recorded letters as letters. An inkjet recording apparatus using such a pigment-based ink needs a mechanism for stirring the ink in a container for preventing the trouble.
As a background art of this technical field, an inkjet recording apparatus including “an ink container and a stirring device” and an inkjet recording apparatus wherein “a stirring bar of a magnetic body is disposed in an ink container and a stirrer and a motor are disposed in a lower part of the ink container, and the rotation speed of the stirring bar is controlled”. In this literature, the outline of a structure such that the stirring bar in the ink container and the motor in the lower part of the ink container rotate at the same speed is illustrated in FIG. 5, but a specific structure of the stirrer is not disclosed.
In an inkjet recording apparatus for a pigment ink, a stirrer is used for stirring an ink in a container, and a method in which the ink is stirred while whirling up the ink by rotating a stirring bar in the container is adopted. In such an inkjet recording apparatus for a pigment ink, when the ink is left as it is without stirring for a certain period of time, a pigment component in the ink in the ink container precipitates in a container bottom part and prevents the normal operation of the stirring bar in some cases. Therefore, a stirrer mechanism capable of rotating a stirring bar by a larger rotary torque is desired.
The inventive inkjet recording apparatus provides an inkjet recording apparatus having a stirrer mechanism which rotates a stirring bar in an ink container by a larger rotary torque.
In order to solve the above-mentioned problems, for example, configurations described in the claims are adopted.
The present application includes a plurality of means to solve the above-mentioned problems. One example of the means is an inkjet recording apparatus including an ink container which stores an ink for printing on a printing object, a nozzle which is connected to the ink container and ejects the ink, a charging electrode which charges the ink to be ejected from the nozzle and used for printing, a deflection electrode which deflects the ink charged by the charging electrode, a gutter which collects the ink that is not used for printing, and a stirring mechanism which stirs the ink stored in the ink container, wherein the stirring mechanism includes a stationary shaft and a rotating body which rotates around the stationary shaft, and is placed in a lower part of the ink container.
According to the inventive inkjet recording apparatus, an inkjet recording apparatus having a stirrer function to rotate a stirring bar in an ink container by a larger rotary torque can be provided.